Transparent distributor cap



Aug. 15,1939. `w. SHERMAN v 2,169,595

TRANSPARENT DISTRIBUTOR GAP Filed Aug 21, 195'/ ATTORNEY Patented Aug. 15, 1939 UNITED STATES PATENT OFFICE TRANSPARENT DISTRIBUTOR CAP Sylvania Application August 21, 1937, Serial N0. 160,263

2 Claims.

My present invention relates to a novel construction and arrangement of a transparent cap for distributors of the ignition systems of internal combustion engines.

In my copending application, Ser. No. 59,674, I have described and broadly claimed a novel constitution of a transparent distributor cap.

The object of my invention is to devise a novel distributor cap, preferably of glass, which can be economically manufactured, and, which can be molded and assembled at a minimum cost.

In my copending application, Ser. No. 59,674, I have shown the contact members as having the upper portions seated in a conical aperture in the cap. I have found in practice that such a design creates a tendency for the contact members to exert a wedging pressure against the bottom of the cap which in some cases causes the cracking of the glass.

In my present invention I have devised novel means to overcome this action and to retain the contacts in fixed, spaced relationship.

It further comprehends a novel construction of a body portion, a novel construction of a cover, and a novel construction oi contacts.

Other novel features of construction and advantage will hereinafter more clearly appear in the detailed description and the appended claims.

For the purpose of illustrating the invention, I have shown in the accompanying drawing, preierred embodiments thereof, which in practice will give satisfactory results. It is, however, to be understood, that these embodiments are typical only, and that the various instrumentalities of which my invention consists can be variously arranged and organized, and the invention is not limited to the exact arrangement and organization of these instrumentalities as herein set forth.

Figure l is a top plan view of a distributor cap embodying my invention.

Figure 2 is a section on line 2 2 of Figure l.

Figure 3 is a bottom plan view of the cover.

Figure 4 is a top plan View with the cover removed.

Figure 5 is a side elevation of the body portion of the cap.

Figure 6 is a sectional detail, showing more particularly the manner in which the contact is seated in the body of the cap.

Figure '7 is a bottom plan view of a portion oi Figure 2, showing more particularly the heXagon shaped recess in the body portion.

Figure 8 is a modied form oi cover.

Similar numerals indicate corresponding parts.

Referring to the drawing:

I designates the body portion of a distributor cap embodying my invention.. The cap is inter nally chambered as at 2, and has a closed tcp wall 3. The top wall 2 has molded in it the contact receiving apertures which at their 5 upper portions have a hat wall and a haii round wall 6. The upper portion is the same as the lower portion, but is oi larger diameter, and having a. iiat wall as i, and a half round wall as at ii. The purpo o1" this 10 construction is to prevent relative rotation between the contacts 9, which are electrically nected with the spark plugs oi the engine. .v apertures are each provided with a fiat seating portion IG. This construction prevents any '.:fedg- 15 ing action of the contacts against the body of the cap.

The contacts ii are shaped to fit the apertures in the top wall, having each a half round side I3, and a iiat side I4 at the upper portion. The 20 contacts 9 are each provided with a fiat suriace, as at I5, to engage the seating portion iii, in the cap body. The flat faces of the contacts 9 are preferably disposed towards the center of the chamber 2, to form elongated surfaces to cooperate with the conventional distributor arm. The contacts are provided at their upper ends with upwardly projecting pins or points I6.

The chambered portion. is provided at its central portion with a heXagonally shaped recess Ii', 30 and a hole I8, adapted to receive a high tension contact member I9 in threaded engagement with a retaining member 2i), and a terminal. receiving member 2|. 'I'he member IS may also be provided with insulating washers 22, and the lower 35 portion may also have its contact bearing portion mounted on a spring 23 and retained on the member I9, as shown in Figure 2, by the spring.

The retaining nut 2t, bears against a raised boss or central enlargement 24, molded in the 40 top wall of the body portion I.

This boss 24 forms an insulating member to prevent shorting between the high tension contact and the conductor contacts.

IThe cap is provided with a cover 25. The cover 45 25 is provided in its bottom face with half round grooves 26, opening through the side wall oi the cover, and adapted to receive the conductors 2i'. The cover 25 is recessed as at 23 so as to iit over the boss or circular po-rtion 2t and is also pro- 50 vided with a recess 29 to receive the mem er i9.

The conductors 2 and the contacts s are retained in assembled positions by the pressure of the cover against them.

The cover 25 may be turned to allow the termi- 55 nals 2'! to extend in different directions from the cap.

In assembling the distributor cap the contacts are dropped into their apertures in the top wall of the body portion, and interlock with the walls of their apertures to prevent relative rotation of the contacts and body portion. The conductors are then pressed over the points I6 of the contacts 9. The cover 25 is then placed in pcsition and theV terminal receiving member 2l screwed down on the member i9, thus securing the cover in assembled relation with the body portion. The high tension wire is then inserted in the terminal receiving member 2|.

The body portion of the cap is provided with an annular bead 3B forming a shoulder for a ring 3 l, which cooperates with the conventional spring clips which hold the distributor cap in assembled position on the distributor.

The body portion and cap are preferably transparent so that the working conditions of the distributorV can be visibly determined.

If a contact is burned or damaged, it can be readily replaced by unskilled labor. All that is necessary is to remo-ve the transparent cap from its body portion, replace the damaged contact, and secure the cap on its body portion.

In order to prevent moisture entering between the cover and body portion, the body portion is provided with a peripherial annular groove 33 to receive an annular flange 32 on the cover.

In the form seen in Figure 8, the construction is similar to that already described except that the conductor receiving grooves in the modified form of cover shown are radially instead of tangentially arranged in the cover.

It will now be apparent that I have devised a new and useful transparent distributor cap which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description, and while I have, in the present instance, shown and described preferred embodiments thereof which will give in practice satisfactory and reliable results, it is to be understood that these embodiments are susceptible of modification in various particulars WithoutY departing from the spirit or scope of the invention or sacrificing any of its advantages.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The combination of the body portion of a distributor cap and removable contacts, said body portion having spaced apertures, half round at their lower portions merging into a ilat seat, the 3 apertures above said seat having a curved peripherial wall merging into a straight wall, and removable contacts in said apertures having a iiat wall to engage said seat, with the portion above said seat having a curved peripherial wall merging into a straight wall, and with the lower portion of the contacts half round in contour. whereby cooking of the contacts in the apertures of the body portion is prevented.

2. The combination with the chambered body portion of a distributor cap, of a high tension contact, secured centrally in said chamber, and circumferentially spacedrremovable contacts surrounding said high tension contact, said body portion having apertures to receive the removable contacts and having a half round wall, a flat seat merging into a half round and a straight wall, said removable contacts having a half round wall,V a at shoulder, and having a half round and a straight wall, whereby when the removable contacts are in place they are centered in their apertures in the body portion and equally spaced from said high tension contact.

WILLIAM SHERMAN. 40 

